SOURCE

let a = 0.0;
let x=0;
let y=0;
let r=50;
function setup() {
    createCanvas(500,500);
    colorMode(HSB,360,100,100);
    //background(120);
}
function draw(){
    a+=2;
    noStroke();
    fill(random(160),100,100);
    r=random(50,150);
    y=r*sin(radians(a))+250;
    x=r*cos(radians(a))+250;
    ellipse(x,y,30,30);
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/1.1.9/p5.min.js"></script>